<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>填写用户名</title>
</head>
<body>

<form action="session.jsp" method=post>
<pre>
<input type="text" name="userName" value="请输入用户名"  onfocus="if(this.value=='请输入用户名'){this.value=''}">

<a href="session.jsp"><input type="submit" value="提交" name="submit"></a>
</pre>
</form>

</body>
</html>